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1.
Summary Crossability barriers between the tetraploid Ulmus americana and five other diploid elm species were investigated using both fluorescence and scanning electron microscopy. Both pollen germination and pollen tube development were inhibited in all interspecific crosses. Pollen tube behavior on the stigma of U. americana was unchanged when pollen of a colchicine-induced U. pumila tetraploid was substituted for diploid U. pumila pollen.Self-incompatibility was observed in one of two American elms studied and manifested itself via reduced pollen germination and inhibited pollen tube growth on the stigma surface.The results indicate that crossing barrier(s) between U. americana and other elm species occur at the stigma surface and operate independently of ploidy level. This conclusion is discussed in relation to current breeding efforts to transfer Dutch elm disease resistance into the American elm via interspecific hybridization with Eurasian elms. 相似文献
2.
José Manuel Alonso 《Euphytica》2005,144(1-2):207-213
Pistil and pollen behavior during self- and cross-pollinations in 10 inbred almond seedlings with self-compatible genotypes
and self-incompatible phenotypes were studied. Pollen from these inbred seedlings was examined for the pollen tube growth
in self and non-self styles, while pistils from these seedlings were tested for their ability to support self and non-self
pollen tube growth. Pistils and pollen of inbred genotypes were compatible with unrelated genotypes but the pistils were unable
to support the growth of related pollen, which showed a slower tube growth rate. This may be a consequence of inbreeding,
resulting in a silenced self-compatibility or cryptic self-incompatibility in some genetically self-compatible genotypes.
This reaction would be a mechanism favoring crossing with unrelated genotypes and reducing inbreeding in future generations. 相似文献
3.
Effects of gamma irradiation on in vitro pollen germination of different Cucumis species 总被引：6，自引：0，他引：6
Summary Pollen grains of 14 Cucumis accessions were irradiated with 0, 1, 2, 3 or 4 kGy acute gamma rays and germinated in vitro directly afterwards. Pollen germination was significantly reduced by increasing irradiation dose for all species, except C. melo var. agrestis. Pollen tube growth was generally reduced likewise. Pollen of two C. anguria subspecies was most sensitive to irradiation. Sensitivity of the pollen with respect to pollen tube growth in relation to irradiation dose was inversely related to total DNA amount per nucleus. In vitro germination was not related to DNA amount per nucleus. Results show that the examined Cucumis species, especially C. melo var. agrestis, are sufficiently resistant to irradiation to be used as donor species for in vivo egg cell transformation of the cucumber. 相似文献
4.
P. van der Valk S. E. de Vries J. T. Everink F. Verstappen J. N. de Vries 《Euphytica》1991,53(3):201-209
Summary To facilitate the introgression of desirable traits of Allium fistulosum into the genome of A. cepa, several accessions of the hybrid between these species were pollinated with A. cepa as the recurrent parent, and in vitro ovary and ovule culture were performed to obtain an increase in the recovery of backcross progeny. Compared to the results obtained from seed development in planta, the increase in the number of backcross progeny was generally very limited, and in some cases even a decrease was found. Raising the sucrose concentration in the ovary culture medium resulted in a higher frequency of ovules developing back seed coats but this was not followed by an increase in the number of backcross progeny obtained. Pollen tube growth of A. cepa was disturbed in the styles of the interspecific hybrids. Per ovule, frequencies of micropylar penetration exceeded frequencies of backcross progeny only to a limited extent. Hence, it was concluded that in the tested interspecific hybrid accessions the attainable gain in viable backcross progeny by the application of in vitro culture techniques is limited by strong pre-fertilization barriers acting at the level of stylar incongruity. 相似文献
5.
The effect of cut style and placental pollination on fertilization efficiency was studied for compatible Aechmea fasciata plants. These alternative in vitro pollination techniques resulted in lower penetration rates of the ovules by pollen tubes in comparison to pollination on
the stigma. An explanation was found in the intervention of the normal pollination process,through which less pollen-pistil
interactions were built up. After cut style pollination the percentage of ovule penetration by pollen tubes increased when
a longer style part was left at the ovary. Probably fewer factors that control pollen tube growth are present in the lower
style part. Pollen germinated on the ovules after placental pollination but only rarely penetration of the micropyle by a
pollen tube occurred. Activation of the ovary, induced by in vivo prepollination for 6 hours, and pollination two days after anthesis did not increase the fertilization percentage. Grafting
a style with active growing pollen tubes to ovules on the placenta (placental grafted style pollination) resulted in a higher
fertilization percentage. Pollen tube growth through the style was essential for pollen tube guidance to the ovules and penetration
of the micropyle.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
6.
Summary A quantitative examination of pollen grain germination and pollen tube growth within the overy wall was made in selected wheat × tetraploid H. bulbosum hybridizations, to investigate the effect of the wheat and the H. bulbosum genotype on these characters. As expected, variation at the known crossability loci had no effect on pollen grain germination. The frequency of pollen tube penetration of the ovary wall was, however, severely reduced when the dominant alleles were present. Pollen tube penetration was nevertheless observed in 3 of the 110 ovaries examined of the non-crossable cultivar Highbury. The H. bulbosum genotype had a much smaller effect on these characters, but significant differences between the clones were observed in the numbers of pollen tubes initially penetrating the ovary wall. Although two H. bulbosum genotypes showed no significant differences in the number of ovaries with pollen tubes at the base of the ovule, significant differences in the frequency of fertilization were observed. The possible cause of this discrepancy is discussed.The frequency of fertilization in crossable wheat × H. bulbosum hybridizations was improved by the application of gibberellic acid within 10 minutes of pollination, and reduced by an increase in the ambient temperature from 20°C to 26°C. Fertilization following the pollination of non-crossable wheat genotypes was not affected by either of these factors. 相似文献
7.
Alice M. Evans 《Euphytica》1962,11(3):256-262
In this investigation, pollen tubes were traced in intraspecific and interspecific crosses in Trifolium. Pollen tube growth was slower in the interspecific crosses examined but no failure of pollen germination was observed. Incompatibility of the pollen tube and stylar tissue proved to be an important pre-fertilization barrier to compatibility and a parallel could be drawn between the success of the pollen and the success of vegetative grafting of the genotypes. 相似文献
8.
Self-compatibility was examined in 22 almond samples that were selected based on their generic and physiological characteristics. Polymerase chain reaction was also done with consensus primers. Pollen tube growth and nut set analyses were carried out on partially bagged limbs after self-pollination treatment. In spite of the fact that all genotypes had the S f-allele and pollen tube growth were similar, nut set exhibited an alternate year characteristic that ranged from 16.2% to a maximum of 24.7%. This was the highest treatment after self-pollination. Difference existed between genotypes could be due to the genetic constitution of each genotype, is explored in set that is diminished by inbreeding, which diminish gene aggregation in different members of a progeny. In addition, flower morphology could also influence set in bagged limbs. Furthermore, with regard to flower sterility and bud density in relation to both pollination success and ecological condition availability, these traits must be considered when examining production in self-compatible almond orchards, e.g.,—the impacts accompanying inbreeding and effective autonomous self-pollination. 相似文献
9.
Effects of Temperature on Pollen Tube Growth and Fruit Set in Reciprocal Crosses Between Cucumis sativus and C. metuliferus 总被引：1，自引：0，他引：1
Interspecific hybridization between Cucumis sativus and C. metuliferus may be used to introduce disease resistance into the cultivated cucumber. Hybrid plant development, however, is restricted by strong barriers to crossing. The present study was undertaken to examine temperature effects on pollen tube growth and fruit set in reciprocal crosses between C. sativus and C. metuliferus. When crossing C. sativus×C. metuliferus, at 20°C, pollen tube growth was arrested in the stylar region of the pistil and no fruits containing embryos were found. However, at 23° and 26°C, C. metuliferus pollen tubes penetrated into the C. sativus ovules. The enhanced pollen tube penetration was correlated with improved embryo development. Although pre-fertilization barriers were overcome, post-fertilization barriers caused abortion of hybrid embryo development at the globular stage. No effects of higher temperatures were found in the cross C. metuliferus×C. sativus; Pollen tubes were generally arrested in the stylar region of the pistil. 相似文献
10.
Summary Pollen of 4 Cucumis sativus genotypes and of the related species C. metuliferus and C. zeyheri 2x was irradiated with four doses of -rays: 1, 2, 4 and 5 kGy. Higher radiation doses were found to inhibit germination and pollen tube growth in vitro with C. sativus, the most sensitive species.Irradiated pollen of cucumber never performed normal fertilization. However, after radiation with 1 kGy, cucumber pollen was able to occupy all available ovules, of which about 50% developed into empty seeds without embryo. This makes 1 kGy-irradiated maternal pollen less suitable to serve as mentor pollen in interspecific hybridizations. Doses of 2 kGy and more appeared to eliminate the ability to compete for ovules, while fruit set after a 2 kGy radiation was still high. 相似文献
11.
Pollen and pistil morphology, in vitro pollen grain germination and crossing success of Lens cultivars and species 总被引：1，自引：0，他引：1
Morphological and in vitro germination characteristics of pollen altogether with pistil and style length were analysed, so as to carry out a morphological comparison between different lentil (Lens culinaris Medik.) cultivars and wild species, as well as to correlate the morphological and functional statistics with data regarding crossing success. Pollen length and width in the different genotypes were found to have a positive and highly significant correlation with pistil and style length and in vitro pollen tube length. A cluster analysis detected two different plant groups, namely, (i) large‐seeded L. culinaris (macrosperma), and (ii) a second group formed by two subgroups, a first subgroup with L. ervoides standing alone and a second subgroup including small‐seeded L. culinaris (microsperma) and the wild L. culinaris ssp. orientalis, L. odemensis, L. nigricans. A high and significant correlation was detected between crossing success and phenotypic similarity (r > 0.98; P < 0.05), therefore implying that phenotypic similarity, based on pollen morphology and in vitro pollen length together with pistil and style length, is a good predictor of hybridization success. 相似文献
12.
J. Ballester R. Bo&#;kovi&#; I. Batlle P. Arús F. Vargas M. C. de Vicente 《Plant Breeding》1998,117(1):69-72
A progeny obtained from the almond cross ‘Ferragnès’בTuono’ (Prunus amygdalus Batsch) was used to study the self-incompatibility trait in three different ways: fruit set, pollen tube growth and stylar ribonuclease activity. As expected from the genotypes of the parents, all progeny appeared phenotypically as self-compatible. However, the progeny could be scored for the segregation of stylar ribonuclease isozymes and thus allowed the incompatibility locus to be placed on the almond linkage map. 相似文献
13.
A pollen selection study for drought tolerance using Poly Ethylene Glycol (PEG) as a selective agent was conducted in sorghum.
Ten genotypes of sorghum suitable for post rainy season were crossed to cytoplasmic male sterile line 104A and three genotypes
to 116A producing 13 hybrids. Two sets of 13 hybrids with and without pollen selection were produced. PEG at 36 per cent was
applied to stigma and stylar tissue one hour before pollination for pollen selection (selective fertilization) and no treatment
for control (nonselective fertilization). Hybrids thus produced through selective and non-selective fertilization were tested
in moisture stress environment during post rainy season. The hybrids obtained through selective fertilization produced significantly
higher mean grain yield compared to hybrids obtained through non-selective fertilization. The results indicate that selective
fertilization through in vivo pollen selection using PEG as selective agent was effective in improving moisture stress tolerance of the progeny in sorghum
genotypes studied. Further, the pollen selection also had influence on plant height, panicle length, panicle width, panicle
weight and grain mass. Thus,the pollen selection had a significant effect on grain yield through its components and developmentally
related traits. Pollen selection for osmoticstress tolerance in sorghum influences the growth and vigour of the plants resulting
in superior progeny in moisture stress environment. The analysis of individual crosses indicated that pollen genotype selection
was able to favour performance of the progeny. However, the pollen selection had positive effect in majority of the hybrids
and the study demonstrates the transmission of the selected trait from pollen generation to progeny.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
14.
Summary Pollen grains from selected cutivars of almond [Prunus dulcis (Mill.) D. A. Webb] and peach (Prunus persica
Batsch L.) were exposed to a range of temperatures between 1°C and 34°C on a thermogradient plate. Pollen germination at temperatures below 9°C was conspicuously greater in almond than peach. Miximal germination percentages were attained at about 16°C (almond) and 23°C (peach). The two species did not differ in their capacity for pollen tube elongation over a broad range of temperatures. Maximal pollen tube elongation occurred at temperatures 5°C to 8°C higher than maximal pollen germination. Species affiliation appeared to be of much greater consequence than chilling requirement or bloom date of the sporophyte in predicting gametophytic response to temperature. 相似文献
15.
Summary Germination of pollen grains and growth of pollen tubes were studied to determine the cause of barreness in crosses among annual Cicer species. In vivo and in vitro time-course studies and fluorescent microscopy revealed no pollination incompatibility among the selfs, crosses and reciprocals of C. arietinum L., C. reticulatum
Lad. and C. cuneatum
Rich. In general, Cicer pollen grains germinated and grew on styles of Cicer species. Pollen tube growth was characterized by irregularly spaced and intermittent callose deposits. Failure of seed formation in interspecific pollinations may be attributed to the slowness of pollen tube growth or collapse of fertilized ovules. In addition to these causes, shortness of stamens and sparsity of pollen grains were responsible for flower drop in natural selfs. Although the number of pollen tubes entering the micropyle in interspecific pollinations was low, it may be possible to grow the fertilized ovules on an artificial medium to obtain F1 plants. 相似文献
16.
Chalermpol Phumichai Yukiko Ikeguchi-Samitsu Masaki Fujimatsu Satoshi Kitanishi Akira Kobayashi Motoyuki Mori Kazuyoshi Hosaka 《Euphytica》2006,148(3):227-234
Summary
S-locus inhibitor gene (Sli), which can inhibit gametophytic self-incompatibility in diploid potatoes and alter self-incompatible to self-compatible plants, was introduced by crossing into 32 diploid genotypes as females and its expression in the F1 and S1 progenies was investigated. We found that the expression of self-compatibility in the F1 hybrid progeny depended largely upon the female genotypes and partly upon the male genotypes (=Sli gene donor clones). Successful females produced hybrid plants, in which 67.1% of self-pollinated plants set S1 seeds. By second selfing upon the S1 plants, an average of 44.2% of self-pollinated plants were self-compatible. Unsuccessful females produced hybrids, most of which were self-incompatible or male-sterile. Restriction fragment patterns of chloroplast DNA (ctDNA) were able to distinguish successful females (S- or A-type ctDNA) from unsuccessful females (W- or T-type ctDNA). A ctDNA high-resolution marker analysis using seven microsatellites and H3 marker supported a higher degree of differentiation between the two groups of ctDNA types and implied a possible interaction between the cytoplasm and Sli gene function. However, it has been known that the cytoplasm having T-type ctDNA and that derived from Solanum demissum (haplotype 26 of W-type ctDNA) cause male sterility, and the present case with unsuccessful females were likely caused by male sterility rather than the failure of Sli gene function. 相似文献
17.
Summary Controlled hand pollinated pistils of rubber were observed using fluorescence microscopy to assess the efficiency of the universally-employed method for the production of progeny for plant breeding. The controlled hand pollination method conducted in the morning resulted in the deposition of a mean of 15.6 pollen grains on the stigma, with no stray pollination observed. Over 36% of the pistils had the potential to set fruit.Pollinations conducted in the afternoon at the normal time of anthesis, had double the fruit set potential of morning pollinations as measured by penetration of ovules by pollen tubes. Pollinator efficiency also varied, with excessive damage to stigmas resulting in reduced pollen germination and tube growth. There were differences between clones in both female and male fertility, in the proportion of pistils with more than three carpels and in the production of small abnormal stigmas. There was no difference in pollen tube growth following self- or cross-pollination, indicating that the self-sterility mechanism of rubber operates in the ovary. Pollen could be stored for 5 days at 5°C and 75% RH with a 22% loss of fertility. 相似文献
18.
Summary F2 and BC1 progenies from crosses between tomato (Lycopersicon esculentum) varieties differing for growth capacity at low temperature were produced under controlled conditions by hand pollination under two temperature regimes (22°C D/15°C N, normal temperature (N), and 15°C D/8°C N, low temperature (L)) with pollen formed under both regimes, resulting in four pollination treatments: NN, NL, LN and LL. Vegetative growth of the offspring was compared under a rather low temperature regime (19°C D/10°C N). Populations from different treatments within the progeny of a particular F1 often differed significantly for average dry weight of 7 weeks old plants, the average of the NN population always being higher. Variances for dry weight were sometimes larger for LN populations, but this never resulted from a larger number of vigorous plants. Differences between populations within each progeny seemed to result in part from differences in the conditions for embryo development. Pollen selection at low temperature did not appear to be efficient for sporophyte breeding in this experiment. 相似文献
19.
Summary Red clover (Trifolium pratense L.) persistence is improved by the growth of adventitious roots from the crown. The effect of one cycle of divergent phenotypic selection for adventitious roots in red clover was evaluated and root and shoot traits including degree of flowering habit correlated. Three classes of single-cross progenies were produced by crossing plants within and between the high and low root selections. Parents and progeny were grown as spaced plants. Adventitious root score and volume were significantly correlated (p<0.05); however they generally had low or nonsignificant correlations with other variables. A significant correlation (r=-0.36, p<0.01) was found between adventitious root score and flowering score (growth type) in 1988 but not in 1989. Significant variation was found among the three classes of single-cross progeny for adventitious root score and crown diameter. The effect of progeny class on score of adventitious roots was not linear, suggesting dominance effects for the absence of adventitious roots may have been present. A narrow-sense heritability estimate of 0.30 was found by midparent offspring regression of the adventitious root score. This low heritability value implies that successful selection would require progeny testing. 相似文献
20.
A series of field experiments was undertaken in order to determine whether resistance to bean common mosaic virus (BCMV) could be incorporated into genotypes of the common bean (Phaseolus vulgaris L.) suitable for cultivation in Zimbabwe without recourse to backcrossing. Six inbred genotypes carrying the resistance-conferring alleles at the loci I and Bc-3 were crossed with five locally-adapted inbred genotypes. The first experiment comprised F3 progeny rows, each derived from a single unselected F2 plant, the second, F3 bulks selected for resistance, and the third, a comparison of selected and unselected F2-derived F4 lines. The number of days to flowering and to maturity, the incidence of mosaic and necrosis symptoms, seed yield and seed size were recorded. There was evidence that late flowering and maturity were associated with BCMV resistance in some crosses, though not strongly enough to present an obstacle to plant breeding. The incidence of virus symptoms and seed yield were influenced by genetic factors additional to the major resistance genes, and variation in seed yield was present not only between bulk populations of crosses, but also between single-row plots of lines within crosses. This indicates that early-generation selection for yield in the presence of BCMV, even among progeny selected for BCMV-resistace, is likely to be effective. However, the variation in yield among F4 lines was least in the highest-yielding crosses, which may represent a limit to successful selection for yield. Seed size was partly under additive genetic control, but there was also evidence of non-allelic interactions. There was no association between large seed size, preferred by consumers, and susceptibility to BCMV in the progeny, indicating that the association between these characters in the parent lines is fortuitous and will not present an obstacle to plant breeding. It is noted that a considerable amount of useful genetic information can be obtained without recourse to elaborate crossing schemes, provided that unselected progeny are included in experiments as controls. The evidence presented indicates that resistance to BCMV can be combined with appropriate values of maturity date, yield and seed size without the need for backcrossing. 相似文献